Images: Left to right: REDAN La Mina, dried blood spot, Microbiology Service (LCMN) at Germans Trias Hospital.
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Credit: IGTP
A study in people injecting drugs evaluated a minimally invasive dried blood spot (DBS)-based test for monitoring hepatitis C virus (HCV) infection. Using DBS samples for HCV RNA detection and genotyping was shown to effectively assess healing after treatment and distinguish between reinfection and treatment failure. The results support the feasibility of decentralized treatment and post-treatment monitoring of injecting drug users who frequently face access to the health care system.Research published in Journal of Medical Virology, was carried out as part of a project supported by the “Overcoming Hepatitis by Microelimination” (CHIME) program and a PFIS grant. The project involved researchers from various institutions, including the Clinical Virology and New Diagnostic Tools study group led by Dr Elisa Martró at the Germans Trias i Pujol Research Institute (IGTP) and Dr Sabela Lens of the Viral Hepatitis Group at the Hospital Clínic. cooperated.
Eradication of hepatitis
In line with the strategy proposed by the World Health Organization to eradicate viral hepatitis as a public health threat by 2030 and the Plan for Hepatitis Prevention and Control in Catalonia in which Dr. Martolo is an active participant. So, her group has focused on: We have been working for many years to simplify the diagnosis of hepatitis C by developing and validating assays that can detect viral RNA using DBS samples. These minimally invasive samples can be collected at Harm Reduction Centers or Substance Dependence Care and Follow-up Centers (known in Catalan as CAS) and can be used to guide a vulnerable population, such as an injecting drug user, to her hepatitis C diagnosis. improve access to Although this new test has shown good clinical performance as a diagnostic tool for detecting HCV RNA before treatment in previous studies by the Clinical Virology and New Diagnostic Tools research group, the use of DBS samples has It was not evaluated as a test for detection. Reinfection after treatment.
A multidisciplinary research group could pursue a project with a new model of hepatitis C care based on point-of-care diagnosis, treatment, and reinfection follow-up at the REDAN La Mina Harm Reduction Center. I made it. Since 2019, through this initiative designed by Dr. Sabella Lens of the Viral Hepatitis Unit of the Hospital Clinic in collaboration with the Clinical Virology and New Diagnostic Tools Research Group of the German Trias y Puyol Institute, injections About 750 people using the drug have been tested (IGTP), headed by Dr Martró of the Microbiology Service (LCMN) at the Germans Trias i Pujol Hospital (HUGTiP), as well as CEEISCAT and the Catalan Public Health Agency. This project was supported by the “Overcoming Hepatitis by Microelimination” (CHIME) program from Gilead Sciences awarded to Dr. Lens. A member of Dr Martró’s group, he is in line with the World Health Organization’s global health strategy that aims to eliminate hepatitis C as a public health problem by 2030.
A model of decentralized care
In this project, Dr. Martolo’s group will clinically validate a previously developed HCV-RNA assay based on DBS for evaluation of healing and detection of recurrent viremia after on-site treatment at a harm reduction center. The purpose was to evaluate performance. A commercial HCV-RNA point-of-care test. In addition, they sought to assess the potential of his HCV genotyping from baseline and follow-up DBS samples to distinguish between reinfection and treatment failure. These assessments (healing and reinfection) are typically performed using venipuncture blood samples taken at a health care center. Recently published results demonstrate how the collection of pre- and post-treatment DBS samples can simplify these assessments in decentralized testing and treatment programs.
“The success of the CHIME project lies in the decentralized diagnosis and treatment provided at REDAN La Mina. Nurses trained in hepatology assessments participated in the study and enrolled and visited participants. Clínic hepatologists also reviewed each case and prescribed decentralized treatment, and Dr. Martró’s group detected and sequenced HCV from DBS samples collected before and after treatment.This pilot. The program includes on-site HCV diagnosis within an hour, treatment at the same center, and follow-up to assess reinfection.”says Dr Lens.
Easier to detect
Reinfection is common in people who inject drugs and should be treated to prevent further transmission of the virus. During early reinfections, which contain only a small amount of blood, low levels of virus may be present, making it difficult to detect in DBS samples. Of the 193 DBS samples tested post-treatment, the DBS-based assay demonstrated 100% specificity and sensitivity ranging from 84% to 96% based on various relevant viral load cut-offs, as well as a cure rate. It showed similar rates (3 months after treatment) as tested. ). It should be borne in mind that her one-tenth of patients with recurrent viremia after treatment had a low viral load. In addition, HCV genotyping allowed researchers to classify 73% of viremia cases as either reinfection or treatment failure.
DBS sample collection was performed before antiviral treatment and after treatment when recurrent viremia was detected by a commercial point-of-care assay. Anna Knott, the original author of this article (who will be part of her PhD), explains: “By using DBS, we can sequence the virus before and after treatment and compare the sequences to determine if the virus is the same (indicating treatment failure) or different (indicating reinfection). This information allowed the hepatologist to make a decision ”about the best combination of antiviral agents for the second treatment”.
This study demonstrates the potential for using DBS samples to determine cure after antiviral treatment for hepatitis C in people who inject drugs and to distinguish between reinfection and relapse. Using the DBS sample will allow decentralization of treatment and follow-up, improving access to care for these people. Still, Dr. Martolo points out: “A minority of patients have a low viral load, which may preclude detection and genotyping of viremia in DBS. As a result, individuals at risk of HCV reinfection should be retested (e.g., every 6 months). ) is recommended”.
This study is a collaboration between hepatologists in group CB06/04/0004 of CIBER in Hepatic Diseases (CIBEREHD) and experts in diagnostics and epidemiology in group CB06/02/0057 of CIBER in Epidemiology and Public Health (CIBERESP). made possible through interdisciplinary collaboration. It includes CEEISCAT (Centre d’Estudis Epidemiològics sobre les ITS i la Sida de Catalunya) and is supported by REDAN La Mina (Parc de Salut Mar) and the Catalan Public Health Authority.
reference
Not A, Saludes V, Gálvez M, Miralpeix A, Bordoy AE, González N, González-Gómez S, Muntané L, Reyes-Urueña J, Majó X, Colom J, Forns X, Lens S, Martró E. Usefulness of Dried Blood Spot Samples to Monitor Hepatitis C Treatment Outcomes and Reinfection in People Injecting Drugs in Testing and Treatment ProgramsJ Med Virol. 2023 Feb;95(2):e285
journal
Journal of Medical Virology
Survey method
observational study
Research theme
people
article title
Usefulness of Dried Blood Spot Samples to Monitor Hepatitis C Treatment Outcomes and Reinfection in People Injecting Drugs in Testing and Treatment Programs
Article publication date
February 2, 2023
COI statement
Conflict of Interest Statement VS Sponsorship of Travel to Attend Gilead Sciences and Cepheid Scientific Conferences. XF has acted as an advisor to her Gilead and Abbvie. SL received speaking and consulting fees from Gilead and AbbVie and research grants from Gilead. EM has received lecture fees and research grants from Abbott GmbH & Co. KG, Gilead, Cepheid, Abbvie and advisory fees from Gilead.
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